BAROGRAPH stamped H.B.N.P. 316 Ca. 1880
BAROGRAPH Stamped H.B.N.P. 316
This precision device records the atmospheric pressure accurately on calibrated graph paper during a week.
The barograph has a clock movement, situated in a rotating drum, which it drives full circle in a week. The spring-driven, week-going brass movement has a platform escapement with hairspring balance. It is wound from the top of the drum with a key. To the right of the drum is a metal multi-chamber bellows (aneroid barometer), which guides an ink-filled recorder pen over the graph paper attached to the drum, indicating the atmospheric pressure in millibar. Next to the drum is a thermometer, which indicates the temperature in degrees Centigrade and Réaumur on a horn register plate.
The brass case has facetted glass windows on all sides so that the mechanism is entirely visible. To the left is the drum on which the atmospheric pressure is recorded. To the right of the drum is the ‘Thermomètre’. The metal multi-chamber bellows is in the middle, whilst the recorder mechanism is to the right. The brass strip situated above the transmission from the bellows to the recorder is marked with the words Baromètre Holostérique. The top of the case can be removed to access the mechanism, which is situated on a rectangular gilt-brass base. It is marked with the stamp H.B.N.P and the number 31524. The whole rests on four engine-turned shaped feet.
Duration: one week
Height 18.5 cm
Width 30.5 cm
Depth 16.5 cm
Bert Bolle, Bert Bolle, Barometers in beeld, Lochem, 1983, Ch. 17 and p. 174.